Friction draft-gear.



C. W. SHERMAN;

FRICTION DRAFT GEAR.

APPLICATION'HLED AUG. 16. m1.

Patented Feb. 5,1918.

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Specification of Letters Patent.

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@rlglnal application filed April 23, 1914, Serial No. 833,898. Divided and. this application filed August It,

i 1917. Serial No. 186,6l l.

To all whom it may concern."

Be it known tlltltl, CLIFTON W SHERMAN, a citizen of the United States, residing at Buffalo, in the county of Erie and fitate of New York, have invented new and use- 7 ful Improvements in Friction Draft-Gears,

teases.

in the accompanying drawings:

Figure 1 is a fragmentary horizontal longitudinal section showing a form of friction draft gear embodying my invention and showing the parts in the position which they occupy when the gear is in normal position. Fig. 2 is a vertical transverse sectionthereof taken in line 22, Fig. 1

Similar characters of reference indicate corresponding parts throughout the several views.

In its general organization this friction draft gear comprises side draft sills or beams 52 which are arranged lengthwise and parallel in the lower part of the car body, a front follower 73 guided between said sills so as to be capable ofmoving forward and backward horizontally, a pair of front stops or blocks 54 secured to the inner sides of the sills and operating to limit the forward movement of the front follower,

v a longitudinal friction cylinder 51 arranged between the sills and having its front end open and its rear end closed by a head 56, a pair of rear stops or blocks 53 arranged on the inner sides of the sills and operating to limit the rearward movement of the friction cylinder, a car coupler 6 provided with a draw bar or shank 8i arranged lengthwise in front of the front follower, and a yoke 55 connected with the draw bar and sliciingly embracing the front follower and friction cylinder.

A solid or one-piece wedge 74 is arranged between the members 75 of a set of friction shoes which engage the bore of the cylinder 51. The inward movement of the latter is resisted by a heavy main spring 76 interposed between the inner ends of the shoes 7 5 and the'head 56 at the inner end of the cylinder, and the inward movement of the wedge is resisted by a light releasing spring 77 interposed between the inner end of the side of the follower 73 and is connected with the yoke 55 engaging with the rear side of the cylinder head. The rear part of the wedgeis provided with inclined-surfaces 78 of a comparatively low or acute angle adapted to stand close to similarly inclined surfaces 79 on the rear part of the opening inner transverse sides of the shoes while the front or outer part of this wedge is provided with inclined faces 80 of a comparatively high or obtuse angle which are adapted to engage with correspondingly-in clined faces 81 on the front parts of the shoes. Between the wedge 74- and the shoes 7 5 transversely operating spring means are arranged whereby the shoes are caused to bear with a greater frictional pressure against the cylinder as the wedge moves inwardly during a buffing'or pulling action. This transverse spring means may be Variously constructed but preferably comprises a plurality of bowsprings 82 made of flat spring metal, each of these springs bearing with its crown against one of the inclined inner faces 28 of the wedge 74 while the ends of this spring are arranged in a recess or pocket 83 formed in the inner side of the respective hoe. T he inner end of the wedge is preferably enlarged and provided with forwardly facing inclined surfaces 90 ar ranged opposite rearwardly inclined faces 91' on the inner ends of the shoes 75, as shown in Fig. 1. By this means the wed e upon being pushed outwardly or forwardly under the action of the releasing spring 77 will be engaged with the shoes so that the latter operate as stops and are pressed.

against the inner side of the cylinder so as to avold chattering noise.

During the part of the inward nioye ment of the wedge when subjected to a half: ing or pulling blow, its inner inclined surfaces 78 first compress the springs 182 and cause the latter to bear with increased friction against the cylinder, the shoes beingh'eld practically at test against inward longitudinal movement by the resistance of the main spring 76. After the wedge has moved inwardly until its inner inclined surfacesf'78 'nearlyengage the corresponding surfaces of the shoes, the transverse springs 82 have i reached the limit of their compression and at this time the outer or front inclined faces 80 of the wedge engage --Wltl1lZhG-GOITBSPODCllDg front inclines of the shoes and operatebeth to increasethe frictional engagement of the latter with the "bore of the cylinder and also to push the same inwardly-g During the last portion of theinwa'rd movement of the wedge under the bufiing or pulling blow the shock is absorbed gradually by theincreased frictional engagement of the shoes with the cylinder and the combined longitudinal spring resistance of the mainand releasing springs order under the most severe service.

I claim as myinvention:

' 1. A frictional draft .gear comprising a member having a friction surface, a set of friction; shoes in frictional engagement with said member, a wedge movable lengthwise forwardly andl' rearwardly between said shoes, longitudinally. operating spring means which resist therearward movement of said wedge and shoes, and transversely Copies of this'patent may be obtained for operatimg spring means interposed between the outer sides of said wedge and the inner sides 'of said shoes.

2. A frictional draft gear comprising a member having a friction surface, a set of vfriction shoes having their outer longitudinal sides in frictional engagement with said friction member and their inner longitudinal sides provided with recesses, a wedge movable lengthwise between said shoes, longitudinal operating spring means whichresist the rearward movement of said shoes and wedge, transversely operating spring means arranged in said recesses and engaging with said wedge, those parts of said shoes and wedges near to'said longitudinally operating spring means being inclined at a comparatively acute angle and adapted to engage with each other as the wedge effects the initial part of its rearward movement, and those parts of the wedge and shoes remote from said longitudinallyop erating spring means being inclined at a less acute angle and adapted to engage each other after the wedge has effected the initial part of its rearward movement causing the shoes to move rcarwardly with the wedge during the last part of the rearward movement of the latter.-

3. A friction draft gear comprising a friction member, shoes engaging the inner surfaces of said member, spring means re sisting the inward motion of said shoes relaively to said friction member, a wedge arranged between said shoes and provided with acutely inclined intermediate surfaces which. are opposite the inner sides of said shoes, acutely inclined outer surfaces which are opposite the outer ends of the shoes and an-enlarged inner end opposite the inner ends of the shoes, spring means interposed between said wedge and cylinder, and spring means interposed between said wedge and said shoes.

CLIFTON W. SHERMAN.

five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

